To Republicans, the deadly September 11 attack on a U.S. diplomatic compound in Benghazi, Libya, was a huge, conscience-shocking security scandal, one that Democrats are shamelessly trying to cover up. To Democrats, the attack was the sort of tragedy that inevitably comes from practicing diplomacy in a dangerous world, one that Republicans are shamelessly exploiting for political gain. Those two views came no closer to agreement during a Wednesday House hearing on the subject.

The hearing by the Republican-led House Government Oversight & Reform Committee was not the first on the events surrounding the death of the U.S. Ambassador to Libya, Christopher Stevens, and three other Americans. Hillary Clinton, who was running the State Department at the time of the attack, testified for hours back in January. But the story was given fresh dramatic life and new narrative details through the testimony of two self-described whistle blowers who had not previously spoken in public: Mark Thompson, acting deputy assistant secretary for counterterrorism; Gregory Hicks, the former deputy of mission in Libya. Joining them was Eric Nordstrom, a former regional security officer in Libya, who had previously testified on the issue.

Virtually no one disputes the basic facts of that violent night, in which a group of militants stormed the compound and battled the Americans for hours. But the sharply different interpretations of why the attacks happened, and how the Obama administration responded, have left many people understandably confused. So has the way “Benghazi” has come to describe several different arguments related to the incident. Here’s a breakdown by TIME’s Washington staff of the key plot lines, and what we know about them:

Could the U.S. military have done more to help? Not according to the Pentagon – and the hearing’s key witness. Aircraft that might have buzzed the compound where the second pair of Americans died – and scared the militants away — were 900 miles north in Italy. “Time and distance are a tyranny of their own,” Admiral James Stavridis, who responded to the attacks as the NATO commander, told Congress earlier this year. Army General Martin Dempsey, chairman of the Joint Chiefs of Staff, estimated it would take as long as 20 hours to get the planes above Benghazi. Hicks testified that he asked the U.S. defense attaché in Tripoli if planes could be scrambled to help those under attack in the CIA annex in Benghazi, a battle that unfolded hours after the initial assault on the nearby U.S. consulate, which killed Stevens, and led to two more American deaths. “He said that it would take two to three hours for them to get on site, but that there also were no tankers available for them to refuel,” Hicks said Wednesday. “And I said, ‘Thank you very much,’ and we went on with our work.” Hicks also testified that a four man team of Green Berets in Tripoli were denied a request to deploy to Benghazi the morning after the attack began, though officials doubt they could have arrived early enough to save lives at the CIA annex. “We continue to believe there was nothing this team could have done to assist during the second attack in Benghazi,” Pentagon spokesman George Little told reporters.

Did the Obama administration distort the truth? Hicks testified Wednesday that his “jaw dropped” when he saw United Nations Ambassador Susan Rice, appearing on multiple talk shows on September 16, largely blame the attack on demonstrations over an anti-Muslim YouTube video. Hicks says it was clear from the outset that what happened in Benghazi was premeditated terrorism. Rice has said she was simply working from talking points produced soon after the attacks by discussion between the CIA, White House and the State Department. New details revealed in a House Republican report show that the CIA’s initial assertion that “Islamic extremists with ties to al Qa’ida participated in the attack” was removed, leading to Republican charges that the language was struck to protect the Obama campaign’s boasts about success in the fight against al Qaeda. But the final version of the talking points did note “indications that extremists participated in the violent demonstrations,” and even the CIA’s original version had called the Benghazi attack “spontaneously inspired by the protests at the U.S. Embassy in Cairo” over the notorious YouTube video. Moreover, David Petraeus, who was then CIA director, testified last fall that he had urged the removal of any reference to al Qaeda to avoid tipping off suspects whom the U.S. was monitoring.

Was the State Department’s internal review legit? One target Wednesday was the independent Accountability Review Board formed to study the attacks. Co-chaired by former Ambassador Thomas Pickering and former joint chiefs of staff chairman Mike Mullen, the board reviewed 25,000 pages of documents and heard testimony from dozens of senior national security officials. The board issued a harsh report which led to the resignation of four State Department employees, but which pointed no specific fingers at senior personnel like Clinton and her top deputies. On Wednesday, Nordstrom called it “inexplicable” to him that the panel didn’t scrutinize the role of top State officials more carefully: “It is not what is contained within the report that I take exception to, but what is left unexamined,” Nordstrom testified. “Specifically, I’m concerned with the [board’s] decision to focus its attention at the assistant secretary level and below.'” Democrats and the State Department challenged that assertion, and on MSNBC Tuesday Pickering likened charges of a cover-up to “Pulitzer Prize fiction.”

What could this mean for Hillary Clinton in 2016? Whether or not Republicans intended it, the shadow of national politics loomed over Wednesday’s hearing. Hillary Clinton completed a generally well-reviewed tenure of Secretary of State, as evidenced by her sky-high public approval ratings. But Benghazi is a clear black mark on her Foggy Bottom record, one that could haunt Clinton if she runs for president in 2016. Conservatives seized on Hicks’s testimony that, in a call with Clinton on the fateful night, he told her that a terrorist attack was underway–a fact that was slow to appear in the administration’s public rhetoric. Still, despite repeated discussion about what Clinton knew and when she knew it, no smoking gun emerged from Wednesday’s hearing, leading one Congressional Democrat to dismiss questions about her role as a “witch hunt.”

Are Our Diplomats Safe Enough? The one thing both parties agree on is that another Benghazi can’t be allowed to happen. But a 2012 Government Accountability Office report suggested that embassy security remains vulnerable so long as the State Department maintains missions in dangerous locations amid staffing shortages. President Obama’s new budget includes $4 billion to improve security at America’s more than 270 diplomatic posts worldwide. That includes a $2.2 billion boost–proposed by the Accountability Review Board–in State’s embassy security construction budget to fund new facilities in high-threat areas. (Congress has yet to approve the funding.) The Pentagon last month deployed the first of 500 Marines to Spain as part of a new rapid reaction force that can respond to emergencies in northern Africa. The Marines are also working with the State Department to add an additional 1,000 troops across the globe, nearly doubling the size of their current embassy guard force. Meanwhile, the threat remains: on February 1, a suicide bomber detonated an explosive device in Ankara, Turkey, outside the U.S. embassy, killing himself and a Turkish security guard.